Sowing tips for different seeds and composts, first plantings, watch for and deal with new weed seedlings, mulching perennial weeds, growth of winter salads, new vegetables 

New growth, and sowing celeriac

It has been an average winter here, and vegetables both outside and undercover have responded well to alternating frosty and damp weather. Leeks and purple sprouting are starting to look full of healthy leaf, garlic and broad beans are growing strongly, while parsnips are not shooting too much and give welcome harvests.

From mid March there are opportunities to sow and plant outside, and many more to sow undercover, starting now with celeriac because it needs a long time to grow. On the forum, John has pointed out how different companies’ seed packets offer conflicting advice about sowing depth, some saying to cover seeds with 1cm (½ in) of compost, others saying to leave seeds on the surface. I have always done the latter as I understand they need light for germination, then I cover the seed tray with glass to keep the surface moist, and I don’t water again for a fortnight or so, when seedlings are usually first visible. A few appear after as long as three weeks, and its the same for celery.

Keeping ahead of weeds

Its a crucial time now for staying on top of new weed growth. Many gardeners who come here are impressed by the weed-free beds, and its not difficult to achieve as long as you watch for new germinations and tackle them when tiny. Any dry days are good for this, to run a rake shallowly through compost on top of beds, or to pass a hoe through it. This quickly dislodges many weed seedlings, many too small to be noticed, and you can save so much time that would otherwise be spent weeding later.

For example I am now noticing fathen seedlings in the composted cow manure I spread last autumn, hundreds of escholzia where they flowered, goosegrass and speedwell in some flower borders.

First plantings

Using fleece allows you to plant early in colder areas too, because of how it warms the soil beneath so quickly, even on days of cold wind. Sunlight in late March is already strong, equivalent to the second half of September.

When seedlings are ready, plant out any of lettuce, spinach, brassicas, peas, broad beans, spring onions – and soon its possible to plant onions and Boltardy beetroot outside.

I often plant seedlings quite small, finding they establish well, and this helps to make space for growing more in the greenhouse, where I have barely enough staging in the spring. We just put a pallet in the tunnel, screwed onto four corner posts, so that I can grow peas for shoots underneath it.

Sowing, and seedlings undercover

See the sowing timeline for lots of ideas. You can sow either in modules or in trays to prick out, use whatever method you feel most comfortable with. Seeds want to grow, as long as they are sown in the right season and with enough warmth, usually the two correlate quite closely so choosing right time is the main thing.

Sowing, compost and seed quality

I have been trying some different composts for propagating and Viridor’s “Revive” is interesting for its large number of woody pieces. I sieved the larger ones out and then sowed radish in both sieved and unsieved compost. Guess which radish have grown faster! – the ones in the more woody, unsieved compost, see photo.

As for seed, last year’s onion seed grew almost nothing, after germinating well in 2014, whereas last year’s Boltardy beetroot seed has germinated correctly, as well as in 2014.

Amazing salad growth undercover

I love March for how the leaves of my overwintered salad plants, sown last September and planted a month later, are changing in quality with every week. They develop more colour, become glossier and are bigger too, so each harvest is heavier than the last. Plants are growing in soil which was surface-composted last May, before plantings of summer vegetables, and I have not spread any more since then, nor fed plants in any other way.

Its a low-input way to grow because there are so few weeds to pull, no new plantings to make and watering is only once a week, thoroughly so that the compost-rich soil has soaked up plenty of moisture. Between waterings, the surface becomes dry and this discourages slugs, reduces weed germination and results in few problems of mildew on leaves.

Mulching perennial weeds

I have an area of new beds, which I mulched with compost last December, to a depth of six inches (15cm). But there are roots of many creeping buttercup in the soil and now they are pushing through the compost, as well as some dandelion and grasses. They are too many to weed with a trowel, so I have laid a light-excluding cover on top, for two months or so.

Any material which excludes light is good to use, in the photos below you can see polythene, landscape fabric and cardboard. The fabric does not exclude all light so it has overlapping cardboard underneath; I like combining them because the fabric holds the cardboard in place, meaning a lot less edges to secure, and it looks nice. The green polythene is farmer’s waste from his lambing polytunnel.

In a Bruton allotment I took the last photo as example of where a path needs mulching, otherwise the couch grass and other grasses will reinvade the mulched beds. One could cover it all with mypex, or lay cardboard on the path and landscape fabric over the whole area.

Oca, yacon, stevia

Oca which I harvested and washed in December has stored well in a hessian sack in my shed, which stayed frost-free. Also in the shed were some yacon buds which I broke off the plant when I dug it up, again in November. They are smaller than a golf ball and are showing promising shoots, so I have potted them on, still needing to keep them frost-free. Stevia has overwintered in pots of compost, they are large, two year old plants in the conservatory, and are starting to regrow now.

Soil quality and tree growth

In December 2012 we planted maiden apple trees of the same size from the same nursery, in two different sites. Those at Homeacres were mulched with compost and fresh manure along a four foot bed. Those at Durslade, Bruton (community orchard) were mulched only with mypex mats, one metre square, and without compost. Then I saw how slowly the Durslade trees were growing and last August a volunteer, Adam, mulched with cow manure – and a lot of this has already been taken in, so he is spreading more. Young trees benefit from feeding and mulching.